Space

Question 1

How was the sun formed?

Answer 1

From a cloud of dust and gas (nebula) pulled together by gravity

Question 2

Describe the life cycle of a star which is the size of the sun?

Answer 2

• Cloud of gas and dust (nebula)
• Protostar
• Main sequence star
• Red Giant
• White dwarf
• Black dwarf

Question 3

Describe the life cycle of a star which is much bigger than the sun?

Answer 3

• Cloud of gas and dust (nebula)
• Protostar
• Main sequence star
• Super Red Giant
• Supernova
• Neutron star or black hole

Question 4

What elements can be produced by a star?

Answer 4

All the elements up to iron

Question 5

What elements can be produced in a supernova?

Answer 5

All the elements

Question 6

How are the elements distributed in the universe?

Answer 6

Explosion of a massive star (supernova)

Question 7

How is a protostar formed?

Answer 7

Gravity causes the hydrogen gas in a nebula to collapse and gather, as the gas particles move faster the temperature rises to millions of degrees celsius. If the temperature gets high enough, the hydrogen nuclei fuse to form helium, this is nuclear fusion

Question 8

What are the two main forces that are acting on a star?

Answer 8

Gravity causing the star to shrink and nuclear fusion causing the start to expand

Question 9

Why does a main sequence star not expand?

Answer 9

The force of gravity and fusion are in balance

Question 10

What is a geostationary satellite?

Answer 10

A satellite that orbits the earth once every 24 hours so it points to the same part of the earth

Question 11

What do circular orbits change?

Answer 11

Velocity (direction of motion), the speed stays the same

Question 12

What happens if the speed of a satellite changes?

Answer 12

The radius of the orbit changes

Question 13

What happens if the speed of a satellite increases?

Answer 13

The radius of the orbit decreases, because at higher speeds the satellite needs a greater force of gravity to prevent it to flying off into space. So:

speed increases - orbit radius decreases - gravity increases

Question 14

What happens if the speed of a satellite decreases?

Answer 14

The radius of the orbit increases, because at slower speeds the satellite needs a smaller force of gravity to prevent it to flying off into space. So:

speed decreases - orbit radius increases - gravity decreases

Question 15

What is red shift?

Answer 15

When the absorption bands have shifted towards the red end of the spectrum (to the left), this shows that the object is moving away from us, since the wavelengths are stretched